This proposal, submitted on behalf of the Society of Craniofacial Genetics (SCFG), seeks support for a scientific symposium on the normal and abnormal development of the central nervous system (CNS). It is to be held on July 9, 1989 at the Lafayette Hotel (Boston, MA) in conjunction with the 26th annual Clinical Genetics Conference (March of Dimes). Some of the topics to be addressed in this symposium by internationally recognized scholars include the epidemiology and etiology of CNS malformations, the ontogenesis of the human cerebral cortex, neuronal cell adhesion molecules, serotonin effects, and the clinically oriented embryology of anomalies such as anencephaly, microcephaly, and holoprosencephaly. The work to be presented is mostly too recent to have had the benefit of review and synthesis, and is likely not to have come to the attention of the average clinician interested in birth defects. It is the goal of this symposium to examine how this new knowledge from disparate fields is internally coherent and enlightening to what we have previously known, and to consider prospects for future research.